Staple and method of stapling



May 19, .1942. p. R. LA PLACE 2,283,814

STAPLE AND METHOD OF STAPLING Fil'ed July 29. 1940 mvsu'ron Dame/7d R La /ace Patented May 19, 19542 sra'res PATENT OFFICE.

STAPLE AND METHOD OF STAPLING Desmond R. La Place, Pittsburgh, Pa., assignor to' Bocjl Corporation, Pittsburgh, Pa., a corporation of Delaware Appiication July 29, 1940, Serial No. 348,195

Claims.

' are employed, is to drive the staple through the overlapping layers of material and clinch the protruding ends of the staple by driving such ends against an anvil. For closing cartons this anvil has to be a thin strip of steel that is inserted under the flaps of the carton, the carton being especially formed to provide for the insertion of the anvil and its removal after the carton has been closed. This is objectionable first, in that only cartons of a style adapted to accommodate the anvil can be stapled shut and also, a free opening is left in the carton at the place where the anvil is removed. In my copending application, Serial No. 343,703, filed July 3, 1940, I have disclosed a staple and method of stapling wherein the staple is provided with a lug or protuberance intermediate the ends of the leg of the staple, and the method of driving is such that after the staple has been entered into the material these lugs are engaged in such manner as toclinch the ends of the staple without requiring the use of any anvil.

The present invention pertains to a staple and method of stapling for use where itis not desired to clinch the staple but which will, never-.

theless, effectively hold. According to the present invention the point of each leg of the staple is provided with a barb which is preferably. integrally formed with the staple and which is preferably of a resilient character so that it will tend to fold in against the leg of the staple when the staple is being driven but which will tend to expand in the fibrous material after the staple has been driven and thus hold the staple from being pulled out.

The invention may be embodied in numerous forms some of which are illustrated in the accompanying drawing wherein Figure 1 is a front elevation of one form of staple with one of the legs of the staple being partially shown in section;

Figure 2 is a side elevation of the staple shown in Figure 1;

Figure 3 is a schematic lapping layers of material as for example, overlapping flaps oi a carton, and showing a staple as illustrated in Figures 1 and 2 driven therein view representing overillustrating the method of the present invention;

Figure 4 is a front elevation of a modified form of staple;

Figure 5 is a side elevation of the stapleshown in Figure 4;

Figure 6 is a front-elevation of another form of staple; and

Figure '7 is a side view thereof Figure 8 is a front elevation of still another form of staple; and.

Figure 9 is a side view thereof.

Referring first to Figures 1 and 2, the staple designated generally as 2 is formed of thin flat sheet metal and it has a bridge portion 3 and legs 4. Integr'ally formed in each leg, preferably by stamping, are barbs 5. These barbs are preferably struck from the sheet metal by an operation of punching such as to separate the barb from the sheet material along its top and side edges leaving it attached to the body of the staple only at the end of the barb nearest the point, i. e., along the line marked 6. The barb is preferably made long enough so as to have some slight resilience. It is preferably slightly, longer than the similar projection disclosed in my copending application above referred to. The barbs are shown as being bent inwardly from the plane of the legs, but theymay be just as well reversed so as to turn outwardly (such for example as shown in Figure 4) or they may be both turned in the same direction similarly to barb shown in Figure 8. The base 6 of the barb is preferably relatively close to the point. and the free top edge of thebarb is considerably below the bridge 3 of the barb, the total length of the barb preferably being less than half the length of the leg of the staple.

Referring now to Figure 3, A designates the lower of two layers of fibrous material, such as corrugated cardboard. and B designates the upper of the two'layers of such material. Usually A and B would represent overlapping flaps of a cardboard carton which are to be secured together in this overlapping relation, but it is not believed necessary to completely illustrate the carton which may be of any known or preferred. construction. Numerous staples are used in spaced relation in securing the two flaps together, but in Figure 3 only one such staple is illustrated. The staple may be driven by any suitably constructed stapling tool. In Figure 3 the outline of the staple before being entered into the material isshown in dotted lines, and the same figure also shows the staple after it has been driven. During the driving of the staple into the fibrous material, the barbs 5 spring in toward the plane of the staple toa slight extent. When the staple has been driven to its full depth into the material, the barbs tend to expand and catch in the material and prevent any reverse movement of the staple. The length of the barb is such that when the staple is driven to its full depth into the overlapping layers of material, the upper end of the barb will be entirely below the top surface of the flap or layer A as clearly shown in Figure 3. Thus the only way to separate the two flaps once the staple has been driven is to pull the fiaps apart with sufiicient force to tear the barb out of the material. As a matter of fact, if the fibrous material is sufiiciently tough, any strain tending to pull the two flaps apart is likely to set up a bending moment due to the pressure against the free edge of the barb tending to bend the end portions of the staple. The staple is preferably of a length such that the point of the staple will not penetrate the lower layer of material so that the contents of the carton will not be damaged when the staple is driven, but where desired, the length of the staple may be such that the points of the staples will entirely pass through the lower layer of material A and the barbs will catch against the undersurface of the fiap or layer A.

By using the staple with a barb, it is thus possible to secure together the overlapping layers of the carton without clinching the staples and still secure them firmly enough so as to meet the requirements and regulations established for the shipping of materials in cartons. The operation of forming the barbs in the staples does not materially add to the cost of the staple.

In the modification shown in Figures 4 and 5, the barb is formed in a slightly difl'erent manner from that shown in Figures 1 and 2. In this figure the barb is struck from the edge of the staple. In these figures, I designates the bridge of the staple and 8 designates the legs terminating in a beveled edge 9. The sheet material of which the staple is formed is cut transversely from one edge of the staple to about the middle of the staple along the line l0, and it is also cut in a longitudinal direction along the line H, and the semi-detached portion I2 formed by these two cutting operations is struck out to form the barb. The barb in this case extends upwardly from the beveled edge 9 and terminates below the middle of the leg of the staple.

In the modification shown in Figures (Sand 7, the staple is formed of narrower stock than the staples previously described, and the barb is formed by folding the terminal portions of the legs back on themselves. In Figures 6 and '7, l3 designates the bridge of the staple and. I4 the legs. The terminal portions of the legs are bent partially back upon themselves to form the barbs IS. The operation of bending the material back upon itself is preferably effected in such manner as to form a sharp point at I6.

The modification shown in Figures 8 and 9 is essentially the same as that shown in Figures 4 and 5 except that the staple is illustrated as being formed of narrower stock and the barbs are shown as being turned in the same direction instead of in opposite directions as in all previous forms. In these figures, I1 designates the bridge of the staple and Hi the legs. The barbslS are barb is turned toward the inside of the leg of the staple.

It will be understood of course, that the barbs of the staples shown in Figures 4 and 5 may be turned in the same direction as the barb shown in Figures 1 and 2 and that the barbs shown in Figures 6 and 7 may be turned outwardly the same as the barbs shown in Figure 4 or may be turned in the same direction as the barbs shown in Figure 8.

While I have illustrated several ways of forming the barbed staples, it will be understood that this is by way of illustration and that the invention is not restricted to the forming of staples in the particular manner described in the several modifications. It is preferred that the barb, however formed, shall be of a length sufilcient to be slightly resilient and it is preferable that it be shorter than half the length of the leg of the staple. While it is desirable that the clinching staple of my copending application shall be ductile, it is preferable that the metal of the staple in the present invention be more resilient in order that the barb will be somewhat elastic or be formed from either sheet metal stock or from wire. depending upon the purpose for which it is to be used, or the type of machine in which it is to be used or the manner in which the barb is formed.

While I have illustrated and-described certain specific embodiments of my invention, it will be understood that various changes and modifications may be made within the contemplation of the invention and under the scope of the following claims.

I claim as my invention:

1. The method of securing together overlapping flaps of a carton formed of fibrous material which comprises driving barbed staples from which the barbs extend at an acute angle into the overlapping flaps through the outer fiap and into the underlying flap to such extent that the innermost edge of the barb is below the outer surface of the innermost fiap.

2. The method of securing together overlapping layers of fibrous material which comprises bringing the layers into overlapping position and then driving a plurality of staples into the overlapping layersfthe staples having resiliently barbed legs thereon adjacent the terminals thereof with the free ends of the barbs terminating intermediate the legs of the staple and sufllciently near the points of the staple that the inner end of the barb catches in the lower layer of material 3. The method of securing together overlapping fiaps of a carton or like article formed of fibrous material which comprises driving staples having initially projecting barbs extending therefrom at an acute angle into the overlapping fiaps, staples being of a length such that the barbed portions of the staples engage entirely the underlying flap, the barbs of the staples being resilient.

4. A new article of manufacture comprising a staple for use in soft material such as fiber cartons and the like having a bridge portion and leg portions, and resilient barbs formed in the leg portions at an acute angle thereto, each barb being susceptible of being sprung inwardly toward the leg of the staple to which it is attached during the driving of the staple and springing out into the surrounding material when driven.

aeeaeie 3 5. A new article of manufacture compflsing a staple having a bridge portion and leg portions, and resilient barbs formed in the le portions, said barbs being adjacent the free ends of the legs of the staple and being of a length less than half the length of the leg of the staple and normally projecting at an acute 5 stantially to its original position.

' DESMOND R. LA PLACE. 

